In reply to Andre.

@Andre,

I agree. This looks like adaptive images to me too. I fear it's going to get very messy for precisely the reasons you have given.

I really don't understand why the images couldn't be made properly responsive instead. That's what the plugin, Soliloquy Lite, manages. While Soliloquy Lite is generally thought of as a slider plugin, I actually use it instead just to show individual responsive images. It works far better than this messy adaptive stuff.